Joseph R. Cass

Stability of the loaded ankle Relation between articular restraint and primary and secondary static restraints

The stabilizing capacity of the ligaments and articular surface in the ankle was determined under defined physiologic loading conditions. The concept of primary and secondary constraints was adapted to the ankle. With physiologic loading, the articular surface ac counted for 30% and 100% of stability in rotation and version, respectively. That the articular surface was the sole source of inversion and eversion stability under the prescribed physiologic loading conditions has not been previously reported. The demonstration that the articular surface resists inversion displacement in the loaded ankle supports the conclusion of previous studies that rotation, rather than inversion, may account for a type of clinically sympto matic ankle instability. Further, ankle instability may occur during loading and unloading but not once the ankle is fully loaded. The results of our study confirm the importance of the anterior talofibular and calcaneo fibular ligaments and suggest an important role for the deltoid ligament.

Tibiotalocalcaneal arthrodesis for arthritis and deformity of the hind part of the foot.

We devised a method for tibiotalocalcaneal arthrodesis to treat deformities or degenerative arthritis, or both, that involve the tibiotalar and talocalcaneal joints. Satisfactory results were obtained in approximately 75 per cent of twenty-one patients; osseous union was radiographically evident in all but three patients. Secondary degenerative changes in the adjacent joints were not evident radiographically during a period of follow-up that ranged from 2.5 to seven years.

Isolated talocalcaneal arthrodesis. A technique using moldable bone graft.

Combined autogenous iliac-crest bone-grafting and fixation with a pin or screw was used to achieve a fusion of the talocalcaneal joint in forty-one adults (forty-five arthrodeses). At a mean length of follow-up of fifty-seven months (range, thirty to ninety-six months), thirty-seven (90 per cent) of the patients were satisfied with the result. Objectively, the results were excellent after thirty-nine arthrodeses (87 per cent), good or fair after five (11 per cent), and poor after one (2 per cent). There was one non-union and one superficial wound infection. At the time of follow-up, no secondary degenerative changes in the associated joints of the hind part of the foot were identified on roentgenograms. The surgical technique appears to be appropriate and effective in the treatment of arthritis of the talocalcaneal joint in adults.

Ankle Instability: Current Concepts, Diagnosis, and Treatment

Our approach to the problem of ankle sprains and instability is reviewed. After diagnostic evaluation (including stress roentgenography, arthrography, or tenography if necessary), most of our patients are treated either by taping if they have a grade 1 or 2 sprain or by casting if they have a grade 3 disruption. If the injury should progress to chronic instability despite this treatment regimen, which is an unusual occurrence, satisfactory reconstructive procedures are available. Indications for acute primary repair are limited.

Ankle Instability: In Vitro Kinematics in Response to Axial Load

This study was undertaken to elucidate the kinematics of hindfoot instability. An axial load was applied to the inverted hindfoot. Unlike prior studies, axial rotation was not constrained. Using computerized tomography, measurements were made on the axial views of external or internal rotation of the leg, talus, and calcaneus. On the coronal views, tilting of the talus at the ankle and subtalar joints was assessed. No tilting of the talus in the mortise occurred with isolated release of the anterior talofibular (ATF) or calcaneofibular (CF) ligament. In every specimen, talar tilt occurred only after both ligaments were released, averaging 20.6°. External rotation of the leg occurred with inversion averaging 11.1° in the intact specimen. The leg averaged a further external rotation of 4.9° after ATF release and 12.8° further than the intact inverted specimens when both ligaments (ATF-CF) had been released. In earlier reports on the subject, the articular surfaces were believed to be the main constraint against tilting of the talus. In those studies, either axial rotation was constrained while inversion was allowed, or vice versa. Based on the data reported here, the ATF and the CF work in tandem to prevent tilting of the talus, and the articular surfaces do not seem to prevent tilting of the talus in the mortise.

Three-Dimensional Kinematics of Ankle Instability following Serial Sectioning of Lateral Collateral Ligaments:

Triaxial kinematics of ankle instability were studied in vitro by applying an inversion force to seven nonaxially loaded cadaveric ankle-foot specimens. In intact specimens, mean maximal adduction of the tibia with respect to the calcaneus was 38° and mean maximal external rotation was 24°; maximal displacement occurred near full plantar flexion. Increases after release of ligaments were as follows: calcaneofibular, maximal adduction 10%, external rotation 3% near 15° of plantar flexion; anterior talofibular, adduction 30%, external rotation 8% at 30° of plantar flexion; both, adduction 41%, external rotation 65% near 0° of flexion; all three lateral collateral, adduction 42%, external rotation 240% in slight dorsiflexion. Regardless of the status of the lateral collateral ligaments, the talus adducted and externally rotated 18° ± 1° with respect to the calcaneus. Hence, collateral ligament release had no effect on subtalar motion.

Detecting vascular injury in lower-extremity orthopedic trauma: The role of CT angiography

As a screening tool, CT angiography has excellent sensitivity and specificity combined with fewer complications compared to conventional arteriography.

Arthroscopic management of native shoulder septic arthritis

BACKGROUND There is little information on the results of arthroscopic treatment of native shoulder sepsis. Therefore, the purpose of this study was to determine the presentation, preoperative indices, intraoperative findings, and outcomes related to native shoulder sepsis treated with arthroscopy. MATERIALS AND METHODS We retrospectively reviewed 50 consecutive native shoulders with septic arthritis between 1994 and 2008. Patients (75% male) were an average age of 66 years. Four patients had bilateral involvement. All underwent arthroscopic irrigation and debridement. The mean follow-up was 31 months (range, 1-185 months). RESULTS Patients were immunocompromised in 57% of cases. The mean preoperative values (normal reference ranges) included white blood cell count, 13 × 10(9)/L (3.5-10.5 × 10(9)/L); erythrocyte sedimentation rate, 66 mm/h (0-29 mm/h), and C-creative protein, 83 mg/L (0-10 mg/L). The average aspiration cell count was 110,988, with a mean differential of 87% neutrophils. The most common organisms were methicillin-susceptible Staphylococcus aureus (44%). Repeat irrigation and debridement was required within the first month in 16 of 50 shoulders (32%). Within 1 year, 17% of patients had died. Final Gächter staging was I or II for 32 shoulders and III or IV for 18 shoulders. CONCLUSIONS Most patients with native shoulder sepsis are elderly and immunocompromised and present with increased inflammatory markers and a supporting aspiration cell count. Patients and surgeons must be aware that after initial arthroscopy, 1 in 3 patients will require additional surgical intervention, whether anticipated or not. LEVEL OF EVIDENCE Level IV, Case Series, Treatment Study.

Acute repair and delayed reconstruction for lateral ankle instability : Twenty-year follow-up study

OBJECTIVES To determine long-term results of patients who underwent primary ligament repair and delayed reconstruction for lateral ligament instability. DESIGN Retrospective. SETTING Outpatient clinic. PATIENTS/PARTICIPANTS Patients who had undergone acute repair or delayed reconstruction at this institution between 1958 and 1977, excluding patients who were deceased or who could not be located. INTERVENTION Forty-eight patients (fifty-three ankles) underwent twenty-two primary ligament repairs and thirty-one delayed reconstruction operations. MAIN OUTCOME MEASUREMENTS Clinical results graded with clinical scale and radiologic results based on stress radiographs and plain film radiographs. RESULTS At an average of twenty years after operation (range 12 to 33 years), patients were satisfied with forty-nine ankles, satisfied with reservations with two ankles, and dissatisfied with two ankles. Clinical results after repair were excellent in twenty ankles, good in one, fair in none, and poor in one. After reconstruction, the results were excellent in twenty-one ankles, good in six, fair in one, and poor in three. In the primary repair group, the mean talar tilt with stress testing improved from 20.7 +/- 10.7 degrees before operation to 2.8 +/- 3.0 degrees after operation. In the reconstruction group, the mean talar tilt improved from 20.7 +/- 8.4 degrees before operation to 2.8 +/- 3.5 degrees after operation. CONCLUSIONS Clinical and radiologic results were similar in the repair and reconstruction groups. The majority of severe (Grade III) ankle sprains may be treated nonoperatively, but if residual instability occurs, late reconstruction should achieve satisfactory results.

Total Hip Arthroplasty For Femoral Neck Fracture: Comparing In-Hospital Mortality, Complications, and Disposition to an Elective Patient Population

Patients treated with total hip arthroplasty (THA) for osteoarthritis (OA) and femoral neck fracture (FNF) between 1990-2007 were compared using the National Hospital Discharge Survey (NHDS). In-hospital, post-operative complications and disposition were compared at six-year intervals to establish trends over time. A total of 2,160,061 THAs were performed for OA, while 174,641 were performed for FNF. Peri-operative mortality and pulmonary embolism rates following elective THA were lower at each interval when compared to THA performed for FNF (P<0.001). Hematomas, infections, and dislocations were also higher in the traumatic group. The FNF group showed improvements with respect to mortality and rates of pulmonary embolism, infection, and dislocation over time. During the most recent interval, there was no difference in dislocation rates between the two groups. The length of stay and the percentage of patients discharging to a rehab facility were significantly higher in the FNF group at each time interval.